Endothelial nitric oxide synthase in the endometrium during the menstrual cycle in patients with endometriosis and adenomyosis

Abstract

Objective: To determine the expression of endothelial nitric oxide synthase in the endometrium during the menstrual cycle in endometriosis and adenomyosis. Design: Immunohistochemical identification of endothelial nitric oxide in endometrial tissues using the monoclonal antibody. Setting: Department of obstetrics and gynecology in a university hospital. Patient(s): The subjects were divided into three groups: 35 patients with endometriosis, 33 patients with adenomyosis proven histologically, and 46 fertile controls. Main Outcome Measure(s): Semiquantitative immunostaining (evaluation nomogram) score in endometrial cells. Result(s): The analyses revealed phase-dependent changes in the expression of endothelial nitric oxide synthase in the surface and glandular epithelia during the menstrual cycle in the fertile controls. The expression was weakest in the early proliferative phase, gradually increased, was most marked in the midsecretory phase, and decreased thereafter. In contrast, stromal cells did not change throughout the cycle. Contrary to expectations, the expression of endothelial nitric oxide synthase in endometriosis and adenomyosis was persistently greater than the control levels throughout the menstrual cycle. Conclusion(s): This study has shown that endothelial nitric oxide synthase is changed in a phase-dependent manner during the menstrual cycle. The exaggerated expression of endothelial nitric oxide synthase in the endometrium throughout the cycle suggests some pathologic role in endometriosis and adenomyosis.